The Failure Patterns And The Significance Of Radiotherapy After Resection And Adjuvant Chemotherapy For Stage ?A-N2 Non-small Cell Lung Cancer

Part one The potential significance of radiotherapy after resection and adjuvant chemotherapy for stage ?A-N2 non-small cell lung cancerObjective: To investigate the survival and failure patterns in the patients treated with curative surgery and adjuvant chemotherapy of stage ?A-N2 NSCLC and to explore the implications for postoperative radiation therapy.Methods: The clinical data of 290 patients with pathologically diagnosed as stage ?A-N2 NSCLC with curative resection and adjuvant chemotherapy from January 2010 to December 2014 in Fourth Hospital of Hebei Medical University were retrospectively analyzed. The survival and patterns of failure were observed. The prognostic factors and locations for locoregional recurrence were analyzed. Overall survival rates(OS),local-Regional failure free survival rates(LRFFS), distant metastasis free survival rates(DMFS)and progression-free survival rates(PFS) were calculated using the Kaplan-Meier method.Results: 1 The median survival time was 31.5 months. The1-, 3- and 5-year overall survival rates were 88.3%, 46.0% and 33.2%, respectively. The1-, 3- and 5-year locoregional control rates were 78.6%, 55.2% and 41.0%, respectively. The1-, 3- and 5-year distant metastasis free survival rates were 76.4%, 45.5% and 39.5%, respectively. The 1-, 3- and 5-year progression-free survival rates were 64.1%, 32.5% and 23.8%, respectively. 2 Univariate analysis showed that clinical N status(P=0.002), pathologic T stage(P=0.035), histological type(P=0.022), type of surgery(P=0.041), the number of positive N2 lymph nodes(P=0.001) and the number of positive N2 lymph node stations(P=0.009) had a significant influence on overall survival.Multivariable analysis demonstrated the number of N2 positive lymph nodes(P=0.017) was the independent factor. Univariate analysis showed that clinical N status(P=0.032), histological type(P=0.046), the number of positive N2 lymph nodes(P=0.005) and the number of positive N2 lymph node stations(P=0.049) had a significant influence on locoregional control. Multivariable analysis demonstrated the number of N2 positive lymph nodes(P=0.009) and histological type(P=0.005) were the independent factors. 3 A total of 172 patients had relapses and/or metastases. There were 70 cases(40.7%) with locoregional recurrence for the first time, there were 80 cases(46.5%) with distant metastasis for the first time, 22cases(12.8%) for both. For left-sided lung cancer, the lymph node station failure sites were mostly in 2R, 4R, 5, 6 and 7,and frequently with the contralateral mediastinum. For right-sided lung cancer, the lymph node station failure sites were mostly in 2R, 4R, 7, 10 R and surgical stump. 4 There were 129 cases occurred distant metastasis, including brain(50cases 38.8%), lung(45cases 34.9%), bone(40cases 31.0%) and liver(23cases 17.8%), and so on.Part two Assessment of postoperative radiotherapy after curative resection in ?A-N2 non-small cell lung cancer with propensity score matching analysisObjective:To investigate the role of postoperative radiotherapy in the patients treated with curative surgery and adjuvant chemotherapy in stage ?A-N2 non-small cell lung cancer(NSCLC).Methods: The clinical data of 313 patients with pathologically diagnosed as stage ?A-N2 NSCLC with curative resection and adjuvant chemotherapy from January 2010 to December 2014 were retrospectively analyzed. Propensity score matching analysis was used to balance the variables differences. The survival and patterns of failure were observed. The role of postoperative radiotherapy and the subgroups that benefited from postoperative radiotherapy were analyzed.Results: After propensity scores matching, the 3- and 5-year overall survival rates of PORT(+) and PORT(-) were 76.5%, 58.3% and 52.1%,40.6%, respectively(P=0.162). The 3- and 5-year locoregional control rates of PORT(+) and PORT(-) were 82.9%, 73.7% and 56.5%, 42.4%, respectively(P=0.036). The 3- and 5-year progression-free survival rates of PORT(+) and PORT(-) were 74.8%, 65.5% and 39.5%, 29.6%, respectively(P=0.021). Subgroups analyses suggested PORT was associated with improved locoregional control rates, such as involvement of subcarinal lymph nodes, tumor diameter ?3cm, multiple N2 metastases, nonskip N2 metastasis and clinical N2 status.Conclusions:1 Clinical N status, pathologic T stage, histological type, type of surgery, the number of positive N2 lymph nodes and the number of positive N2 lymph node stations were prognostic factors for overall survival. And clinical N2, squamous cell carcinoma, positive N2 nodes of more than 3 and multiple positive N2 stations were negative prognostic factors for locoregional recurrence. Locoregional recurrence of left lung cancer frequently involves contralateral mediastinum, while the right lung cancer usually locates in ipsilateral mediastinum.2 PORT could increase the local-regional control rate and progression-free survival rate in stage ?A-N2 NSCLC with curative resection and adjuvant chemotherapy; Patients with involvement of subcarinal lymph nodes, tumor diameter ?3cm, multiple N2 metastases, nonskip N2 metastasis and clinical N2 status may benifit most from PORT.